Selective switch.



Patented Jan. 1, 1918.

H. P. CLAUSEN. SELECTIVE swncn. APP'LICATI M min 020. 29. I916.

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UNITED STATES PATENT- OFFICE;

HENRY CLAUSEN, OE MOUNT VERNON, NEW YORK, ASSIGNOB TO WESTERN ELEC- TRIO COMPANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

SELECTIVE SWITCH.

Indication of Letters Patent.

Patented Jan. 1, 1918.

To all whom it may concern:

Be it known that I, HENRY P. CLAUsnN, a citizen of the United States, residing at Mount Vernon, in the county of Westchester and State of New York, have invented certain new and useful Improvements in Selective Switches, of which the following is a full, clear, concise, and exact description.

This invention relates to selective switches and has for its object a reduction of the trunk hunting interval.

It has been found, in connection with automatic telephone systems in which the step-by-step type of selective switches is used, that a subscriber sometimes succeeds in transmitting a second series of impulses before a selective switch concerned in his connection has sought out and seized an idle trunk and that, therefore, the first impulses in the secondtrain transmitted do not reach the next selective switch, with the result that a wrong connection is established.

A feature of this invention is a set of brushes for each directed position of a selective switch and meansfor starting all in search of idle trunks immediately upon the seizure of such a switch. According. to this feature each set of brushes is moved forward until an idle trunk is encountered when it will be disengaged from the driving shaft and thus left in engagement with the selected idle trunk.

' Another feature of this invention is the means by which aline is extended through such a selective switch. A ratchet member with an auxiliary set of brushes is loosely mounted on the'shaft of the selective switch, and, through an im ulse directed movement, such auxiliary brus es are driven into association with the desired set of brushes of such switch.

According to another feature, trunk hunting and the directed movement of such a switch are accomplished at the same time, providing that a subscriber sends out a series of impulses immediately that such selective switch is seized. In some cases the hunting movement will be completed before the directive impulses are received.

In the drawin Figure lrepresents diagrammatically t e callin subscribers substation connected throug the line switch to a selective switch embodying this invention; andFi 2 is a perspective drawing of a detail of the selective switch of this invention showing a set of brushes and the means for disengaging said brushes from the driven shaft when a set of terminals leading to an idle trunk is encountered.

Referring now to the drawings, let it be assumed that the subscriber at'substation S removes his receiver from its hook and that the line is connected through a line switch (not shown), to the selector switch SS A circuit is thereupon established from ground,

' battery, right-hand winding of relay LE the first position contact and side-switch wiper w, the telephone line and apparatus of substation S the side-switch wiper w and its first position contact, left-hand winding of relay LR to ground. Relay LR is energized in this circuit and by attracting its armatures establishes a circuit from ground, the armature and alternate contact of relay LE winding of the first slow release relay 1, to battery and ground.

The attraction of its armatures by relay 1 establishes a circuit from ground, the contacts 2, the right-hand armature and contact of relay 1, the contact and armature of relay 3, to battery, and ground. Relay 3,

through a pawl 4 and a ratchet 5 acts to rotate the shaft 6 in a direction indicated by the arrow on member 7. Relay 3 in attracting its armature breaks itsown circuit in the well-known manner, and throu h a vibrating action performs the function just described. The rotary action continues until the shaft is completely rotated, when the insulated member 8, making physical contact with the contact 2, opens the circuit for magnet 3 at that point.

Loosely mounted on the shaft 1 are ten brush sets, B to B inclusive, whose brushes 6, b and b are arranged to travel over and make contact with the terminals t, t and t". In their normal positions these brushes rest upon the first set of terminals in their respective rows, and, since the busy'condition of the trunks to which the terminals t, t and t extend is indicated by ground on the test terminals t, such grounded terminals in each case provide a circuit for the energization of a magnet m from ground,'terminal t brush 12 the winding of magnet m to battery and thence to ground. .Through the 5, 5 and 6 en an idle trunk is encountered by this rotating set of brushes the energizing circuit tor the magnet m is broken and collar 10 is allowed to descend until the pin 9 is disengaged therefrom,

ward movement of brush set B serves only to put a greater degree of pressure on the terminals 25 t and t whereby the contact between such brushes and such terminals is more firmly established.

It may happen in this manner that several brush sets are not moved away from their initial position, while others are moved one, two, three or more steps each, and each will in time come to rest upon an idde set of: trunks,

When the subscriber operates his impulse transmitter D which may even occur while the hunting movement is taking place, the well-known intermittent opening of sub scribers circuit causes the rapid vibration of the armature of line relay Thereupon a circuit is intermittently established from ground, armature and normal contact of relay LR, left-hand armature and con tact of relay 1, to a point where the circuit divides, extending in one direction through the relay 11 to battery and ground, and in another direction through the first position contact and side-switch wiper 'w to the vertical magnet VM, to battery and ground. Magnet 11, being slow to release, does not respond to the separate impulses through which it is energized, but remains energized until the train of impulses is completed.

Magnet VM, however, does respond to the 7 separate impulses, and through its armature and a pawl 12 elevates the ratchet member 13 carrying the auxiliary set of brushes B.

The energizing of relay ll results in the establishment of a circuit from ground, the armature and contact of relay 11, the winding of escape magnet 14, to battery and ground, whereupon relay 1% is energized. After the last impulses have been received and relay LE has been maintained in an energized condition for a certain period of time, relay 11 becomes deenergized, and in retracting its armatures dee'nergizes the relay 14, which in turn thereupon steps the side-switch wipers into their second position.

After the first vertical movement of the ratchet member 13, the ofi-normal switch ON is closed and a ground potential from the line switch, indicated by the broken lines,

is projected over the conductor 15, oil-normal switch ON, winding of release magnet 16, to battery and ground. Magnet 16 attracts its armature and releases the holding pawls 17 and 18 into engagement with the notches of the rotary and vertical ratchets,

whereby the rotary and vertical positions attained will be retained until the release o: this switch. lfhe energization of magnet 16 also establishes a circuit from ground con tact and armature of magnet 16, the second position contact and side-switch wiper w through the test brush of the brush set E, to the test brush of the selected brush set, which we may assume to be in this case B, and thence over the terminal 23 to the release trunk of the next seized selective switch.

llt should be noted at this point that the vertical movement of the member 13 and associated brush set E elevates the brushes b 6 and I) in such a manner that they come to rest upon the terminal t and t of like sets leading to the brush sets B to B inclusive, and in such a manner is a connection extended through the proper sets of brushes.

Further manipulation of the impulse transmitter D will result in like movement of other selective switches until the connection is finally established. Upon the completion of a conversation, the removal of v 6 is rotated backward under the influence of the spring 18. During such a backward rotary movement the pin 9 comes into a physical contact with the projection 19 of the collar 10 and the brushes b 79 and b are returned to their normal position from whatever position they may have taken.

What is claimed is:

1. In a selective switch, rows of fixed cir= cuit terminals, a set of brushes arranged to travel over and make contact with. the terminals of each of said rows means for driving said brushes over said terminals, means responsive to an electrical condition denoting an idle condition for disengaging a set of brushes from said driving means, and means for selectively extending a connection through any one of said sets of brushes.

2. lin a selective switch, rows of fixed sir cuit terminals, an individual set of brushes arranged to travel over and make contact with the terminals of each of said rows of terminals, a common actuating means for all of said brushes, an individual means fortoo arranged to travel over and make contact with the terminals of each of said rows, means common to all of said sets of brushes for actuating the same, means responsive to the idle condition of said circuit terminals individual to said sets of brushes for disengaging the same from said actuating means, and means for selectively extendin a circuit through any one of said sets 016%rushes.

4:. In a selective switch, rows of fixed circuit terminals, an individual set of brushes arranged to travel over and make contact with the terminals of each of said rows, actuating means common to and mechanically coupled with each of said sets of brushes means individual to each of said sets oi brushes for disengaging them from said actuating means, said disengaging means being responsive to the idle condition of said circuit terminals, an auxiliary set of fixed terminals connected to said brushes, an auxiliary set of brushes arranged to travel over and make contact with said auxiliary terminals, actuating means for said auxiliary brushes, and directively controlled means for extending a circuit through said switch via said auxiliary brushes, said auxiliary terminals, said brushes and said terminals.

5. In a selective switch, rows of fixed circuit terminals, brushes arranged to travel over and make contact with said terminals, actuating means for said brushes, means responsive to theidle condition of said terminals for setting said brushes ona set of said idle terminals in any of said rows of terminals exteiiding a circuit through said switch in a particular row of said terminals.

In witness whereof, I hereunto subscribe my name this 28th day of December, A. D.

HENRY P. CLAUSEN.

and means independently operable for 

